(a) Field of the Invention
The present invention relates to a thin film transistor array panel and a manufacturing method thereof.
(b) Description of the Related Art
Generally, a liquid crystal display (LCD) is one of the most widely used flat panel displays. The LCD has two panels provided with electrodes formed thereon and a liquid crystal layer interposed between the two panels. Voltages are applied to the electrodes to reorient liquid crystal molecules in the liquid crystal layer, thereby controlling the transmittance of light.
The electrodes are supplied with the voltages through switching elements called thin film transistors (TFTs). The TFTs are required to have high current driving capacity as the LCD becomes large, and it is preferable that channel width of the TFTs are increased.
In the meantime, photo-etching processes are performed to form various patterns on the panels of the LCD through light exposure.
When a backplane for LCDs is too large to use an exposure mask, the entire exposure is accomplished by repeating a divisional exposure called step-and-repeat process. One divisional exposure unit or area is called a shot. Since transition, rotation, distortion, and etc. are generated during light exposure, the shots are not aligned accurately. Accordingly, parasitic capacitances generated between wires and pixel electrodes differ depending on the shots, and this causes the bright difference between the shots, which is recognized at the pixels located at a boundary between the shots. Therefore, the stitch defect is generated on the screen of the LCD due to brightness discontinuity between the shots.